can i borrow a loan without consent from a co-tenant?

[Mike]

sorry but it's me again. ideas just keeps coming up while reading all the items on this site. so to begin i have this sister of mine who wants 50% of the equity and never contributed to all the expenses to maintain the property and was mistakenly add on as a co-owner by my younger sister when she was forced by her in-laws to quit claim. i am currently jobless due to disability and having some kind of problem to keep the property do i have the right to refinance the property without her knowledge and will take responsible to whatever amount i will be borrowing? i don't want to lose the property because it was passed on to us by our mother who passed away in 1995 and it has a sentimental value to me.